any possible way to make install46.iso boot from usb to install to a old laptop

Hello
I'm new to BSD and i want to install openbsd4.6 to my old laptop hp omnibookxe3 (PIII processor @ 800Mhz , 128mb ram and 20gb hdd).
The problem is my laptop has no cdrom or usb boot support but it has a floppy drive which is working . Installation from floppy is ok but my connection speed is very less takes hour or days i dont know .
Right now it has puppy linux in it but i want to install and use openbsd .
Before, i took out the hardisk and connected it to another system to install,but it is very difficult process (opening the laptop and all).So i've got the install46.iso from my friend .

>>Is there any way to make the install46.iso boot from usb drive or any live openbsd's so that i can install it onto the laptop.
I use PLOP boot manager from floppy to boot from usb ports